Improvement in flouh and grist-mills



' A. J. VAND-EGRIFT. Flour and Grit M111. No. 107,311. Patented $611.13, 1870.

".PEIERS, PNOTD LITNOGRAPMER, WASHINGTON. Dv C1 Fig.2.

ANDREW J. VANDEGRIFT, OF OOVINGTQN, KENTUCKY.

Letters Patent No. 107,311, dated Sqacmber 13, 1870.

IMPROVEMENT IN FLOUR AND GRIST-MILLS.

Sched le referred to in these Letters Patent and niaking part of thesame.

To all whom it may concern:

Be it known that I, ANDREW J. VANDEGRIFT, of the city of Ooviugton,county of Kenton and State of Kentucky, have invented new and usefulImprovements in Flour and Grist-Mills; and I do hereby declare that thefollowing is a full, clear, and exactdescription of the construction andoperation of the same, reference being had to the annexed drawing makinga part of this specification, inwhich- Figure 1 is a vertical sectiontaken in lines 3 y, figs. 2 and 4. v

Figure 2 is a top view of the husk-frame of the mill and the bed-stone,the upper stone. or runner having been taken off.

Figure 3 is a view of the pattern for laying off the furrows in thestones, plainly exhibiting the form and mode of obtaining-the same.

Figure 4 is a top view of the upper stone or runner inverted. v

Figure 5 is a vertical section of the same, taken in lines y y.

Figure dis a top view pf my improved irons for hanging and drivingmillstones, showing a form of construction difiering'somewhat from thatwhich I have. adopted.

Figure 7 is a vertical section of the same, taken in linesxx fig. 6.

Similar lettersof reference indicate corresponding parts wherever theyoccur in the several figures.

The nature of my invention consists:

First, in constructing the driving and hanging-irons of millstones, insuch a manner that the hearing points will readily adjust themselvesto'each other 'without shifting or in any way disturbing the point ofsuspension,' or causing a lateral strain on the pivot-. point of thespindle; or, in other words, in providing millstones with perfectself-tram'ming irons, so that the power may be applied in driving themwithout.

interfering with their freedom of oscillation on'the pivoted-point ofthe spindle.

Second, in providing millstoncs with an improved dress, by which thefurrows are out in such a form that the grinding surface and furrows areinoreuniiormly proportioned to each other at all-points, from the centerto the circumference of the stone, and so that the draft of the furrowsshall gradually decrease as the verge of the stone is approached,adverseto' the increase of the centrifugal force generated by the rotarymotion of the running stone, thus accelerating the passage of the mealoutward, near the center, where the centrifugal force is Weak, andgradually less, as the verge is approached,-where the centrifugal forceis greater.

To enable others skilled in the art to fully understand and construct myinvention l will proceed to describeits construction and operation,referring to the accompanying drawing and the letters marked thereon.

A, figs. 1 and 2, is the husk-frame of the mill.-

B, figs. 1 and 2, is the bed-stone.

O, figs. 1, 4, and 5, is the upper stone or runner.

D, figs. 1 and 2, is the spindle, to which the driving power is applied,and upon the upper end of which the upper or running stone is pivoted.

In place of the bale. or balance-iron commonly used in the eye ofmillstones for the purpose of pivoting the stone on the point of thespindle, I construct a cross-head, E, figs. 1, 4, and 5, which issuspended in the eye of the stone by lugs,t t, on either side, beingfitted iu a cast-iron shell, F, figs. 1,4, and 5, which is constructedintwo longitudinal sections, provided with suitable flanges, so that thecross-head may be fitted in, and the two sections bolted or rivetedtogether, forming a substantial support for the cross-head as well as alining for the eye of the stone.

In cross-head E I form a socket for the reception of the point of thespindle, which is properly titted to form a perfect ball-and socketjoint, theceuter of which is exactly in line with the center of the lugst t, as shown plainly bylines o c, fig. 1, drawn horizontally throughthem.

Gross-head E is provided with pendants, d cl, figs. 1 and 4, whichextend down to and fit loosely in suitable slots in the ends of across-driver, G, figs. 1-

and 2, which is fitted firmly on the neck of the spindle D.

Now, when the spindle is made to rotate, it will be readily seen that'-the jaws f f of driver G, fig. 2, coming-in contact with pendants (Z (lof the cross-head, the motiouis transmitted to the millstone, and ascross-head E is hinged by its lugs'on a planewith the center of thepivot, which is the ,point of suspension, and thecenter of voscillation, the points of pendants (Z (Z can swing back andv forthwithout disturbing the eqnipoise of the stone; and, as one jaw of thedriver comes in contact with one of the pendants, the crosshead swingsin the direction of the bearing, and the opposite pendant is, therefore,swung back in contact with the opposite jaw of the driver. The bearingis perfectly equalized on both ends of the driver wit-hont interferingwith'the center of gravity, or the free: dom of oscillation on the pointof suspension, so that arunning stone provided with these irons maybetruly said to be always in perfect tram with its spindle.

In setting these irons, it is not necessary to't-rani the spindle to therunner, as. is the case with other irons in use, but it is desirable tohave the eye in the center and straight through thestone.

To effectthis, .I have adopted .a simple device for tramming the shell Fin the eye of the stone, as shown plainly in fig. 5, so that. my ironsmay be equally applied to stones now in use, as well as new ones, byfirst preparing the eye of the stone by the removal of the old irons,and cutting. the plaster away, so that shell 1 may he set in, as shownin fig. 5; then, by fitting a wooden head, H, in shell 1, with suitable'mortices cut in for the points of pendants (I (Z to rest in, and

'with a small hole in the center for the reception of a small woodentram-spindle, I, which is turned to fit the hole neatly, and also, itspoint being 'properly formed to fit in the socket in the cross-head, andhav iug an arm, J, stiffly hinged at its upper end bya screw, thetramming device is complete, as shown plainly in fig. 5, so that anynovice will be able to tram the shell. inthe center by wedging it inplace, so that the tram-spindle shall stand in the center of the stone,and, so that, when arm J is swept around the quill-point in the endofthe'arm, shall touch the face of the stone at all points alike; which,being accomplished, the shell should be secured inits position by havingplaster poured around it, and the eye should be properly plastered upwhere it has been cut away, and the stone is then ready to be put on i sspindle for the purpose of truing up, the back and eye, by turning\vitha chisel, preparatory to being put in proper running balance,which, being done, the job is completed.

I have thus described my improved irons, as applied to mills, in whichthe upper stone is the runner. They can be, with equal effect, appliedto mills in which the understone is the runner. v

I have also described cross-head E as'bcing hinged by its lugs in theshell of the eye.

This construction may be varied by theinscrtion-of a ring, 21, figs. 6and 7, in the eye, between the crosshead and shell F, so that thecross-head shall be hinged in the ring by its lugs, and the ring, inturn, be hinged by similar lugs in the other-two opposite quarters ofthe circle, in shell 1!, as shown plainly in figs. 6 and 7, the lugs ofthe ring, well as'those of the cross-head, being on a plane with thelines :2, fig. 7. I

This mode of construction provides a perfect universal joint,independent of the pivoted point of the spindle.- .This is myorigiual'plan, but, on account of its being so cumbersome in the eye ofthe stone, particularly of thesmaller size, I have adopted the formhereinbefore set forth and described, as being more substantial, andless. complicated and cumbersome,- more readily and cheaply applied, andfully accomplishing the object songht.- Y

My improvement can he applied in various forms, but so long as anoscillating cross-head or a crosshead with oscillating pendants, isused, substantially as herein set forth and described, I shall considerit an infringen'icut on my invention.

I have also invented an -improveddress to mill= stones, plainlyrepresented in figs. 2, 3, and 4', the ob ject of. which is to preserveva unifbrmityof proportion between the grinding surface and the furrows,at all points from the eye to the verge of the stone, and also toprovide a uniformly decreasing. draft as the verge is approached. This Iaccomplish by a dress consisting of a series of curved fin-rows, withthe feather edge on the convex side. These furrows are each a segment ofa circle. The .leading furrows a, fig. 3, have but little draft at theverge of the stone. Each of the shorter furrows, 'r and u, fig. 3, whichintersect-the leading furrows, between the eye and the draft-circle O,fig. 3, added together. This gives the furrows very little draft at theverge of the stone though they have some draft at that point.

It is essential that pitch-circle T should be more than twice thediameter of the stone, as it is apparent that if the pitch-circle wasjusttwice the diameter of the stone, or smaller, the furrows described}by a tram from the draft-circle O to the verge would bag between thedraft-circle and the verge.

In laying off the dress of a stone, or a pattern for the same, on myimproved plan, I proceed as follows:

I first strike a circle, S, fi 3, which represents the diameter of thestone; I then strike a draft-circle,-

O, fig. 3, for a stone four fcetin diameter. The draftward to the verge,which describes the feather edge of the leading furrow a; I thencontract my tram to strike the line of the back of the furrow, and,having spaced the sections into as many spaces as I want furrows to thesections, so 'that all of the furrows, both short and leading furrows,shall be equidistant from each other at the verge, using in a stone fourfeet in diameter, "twelve sections, and one leading and two shortfurrows to the section, I then strike two more draft-circles, p and q,fig. 3. The diameter of these circlesmay be varied to suit the qualityof stone, for the purpose of giving more or less grinding surface at theeye-,but I regulate the diameters so that the dis tauce from the back ofonefof the leading furrows to i a radiating line from pto (1 shall beequal to the disdance from O to p; 1 then proceed to set my tram so thatwhen one point is set in pitch-circle T, the other shall touchdraft-circle p,- I then set one point of the tram in the lastspace-mzu-kof the section-in circle S, and find. at what point the other point willstrike pitch-circle T, which is found to be 72 I then sweep the otherpoint back from the verge toward the eye until itintcrsects'leadingfurrow a. This describesthe feather edge of furrow u;I then. contract the tram,

and strike the line for the back of the furrow; I then set my tram todraft-c rcle g, and proceed to find point r in pitch-circle T, as in theother case, and sweep from the verge toward the draft-circle q, as inthe former case, and by so doing" describe the line of the feather edgeof furrow '1'," I then contract my tram and strike the back of the samefurrow. This completes one section, .and, if desired, may be laid off ona thin board or metal, an.l cut out fora pattern, as shown in fig. 3,having a hole large enough cut in it, to. fit over the neck of-thespindle, for laying off the bed-stone, and then, by fitting a plug inthe same, with a smaller hole in its center, to fit .over a center pin,which may be set in a piece of wood in the eye; the runner may be laidoff by the same pattern by moving the pattern around the stone, settingthe back of-the pattern to each section-mark, and marking the furrow outby'it. The form of dress plainly shown in figs. 2 and 4 is thusproduced:

This dress has the advantage of uniformity of dis tribution over theface of the stone, and the mode of giving a great draft to the furrowsnear the center, to convey the meal but rapidly where there is'bntlittle centrifugal force, and decreasing in the proper proportion, asthe periphery is approached, tends to equalize the work performed to thetime and space at all points. lhis dress can be readily varied to suitdifferent qualities of stone, or to suit different ,sections of thecountry. t

The number of sections in the circle may he increased or diminished, orthe number of furrows 'to the section may be varied, or the draft at theeye may be varied; but, in any case, the diameter of the pitchcircleshould be at least twice the diameter of the stone, or more.

In order to show clearly the manner in which the furrows cross eachother when the mill is in operation, I have drawn three sections of thedress, reversed, on the face of the stone, fig. 2, and have alsoindicated the direction of the motion of the running stone by an arrowat the verge. i

Having thus fully described the construction and operation'of myinvention,

What I claim therein as new, and desire to secure by Letters Patent, is-

1. Gross-head E, hinged by lugs in the eye of the millstone, on a planewith the center of oscillation on the point'ofthe spindle, substantiallyas set forth and described.

2. Pivoted cross-head E, with pendants d (1, constructed andarranged inthe manner and for the purposes substantially as set forth anddescribed.

A milIstone-dress, consisting in the arrangement of a series of curvedfurrows, a, mange-0m the eye to .the periphery of the stone, and one ormore series of shorter furrows, 'r u, leading from points ofintersection of these to said periphery, with the feathei or grindingedge on the convert side of all the furrows, substantially as herein setfolth.

. A. J. VANDEGRIFT.

Witnesses:

L. F. POTTER, Tnos. STAFFORD.

